The incident occurred on Friday morning at Edison Junior-Senior High School in Lake Station. Students posted a photo of the chalkboard on Facebook, and, apparently after the school resource officer saw it online, the teacher was sent home. He was placed on leave and won’t be back in the classroom until school authorities and police complete their investigation.

The teacher possibly could be charged with a felony depending on how local prosecutors evaluate the police report when it is submitted. The local police chief remarked that “Any kind of threat, especially a threat with a weapon or words of a weapon, may be a criminal act, and that’s what we’re looking at.”

Lake Station Schools Superintendent Dan DeHaven told NBC News Chicago, “We take this situation very seriously; safety is very serious to us.” He also reportedly confirmed that the business teacher did indeed write the threatening note on the blackboard.

ABC News Chicago reports that the educator, who has not yet been identified, has been teaching at the school for about 28 yours and evidently has no disciplinary actions in his jacket. Students claimed that the message was scrawled on the chalkboard after he had a “meltdown” in the classroom.